Coal drill



Feb. 23,1932. c P. BASCOM ET AL COAL DRILL Filed July 1.6. 1928 E QUE. Wm mm drills it was found to be Patented Feb. 23, 1932 UNITED STAT ESPATENT "OFFICE 3 CALVIN P. nAsooM Ann CHARLES woLr, on ST. Lou s,MIssounr COA DRILL Application filed July 16,

This invention relates generally to drills intended for use in miningcoal, the predominant object of the invention being to produce a drillby means of which a hole which is of uniform diameter throughout may bedrilled in a coal deposit in a coal mine.

The most common method of mining coal involves the use of shells orcartridges containing an explosive, which shells or cartridges areintroduced into holes drilled into the body of coal to be mined. Theholes referred to are so located with respect to each other that whenthe shells or cartridges are arranged in said holes, and the explosivein the shells or cartridges exploded, a predetermined section of thewall of coal will be displaced by the explosion and will tumble to thefloor of the mine from which it is subsequently removed.

Prior to this invention the holes into which the shells or cartridgeswere introduced were drilled with the ordinary and well-known coaldrills, but due to the construction of these practically impos sible todrill a hole therewith which would be of even approximate uniformdiameter throughout. i

The shells or cartridges mentioned are located at the extreme innerendsof the holes and because of the irregular or non-uniform diameterofthe holes drilled with the drills formerly used it was necessary,after placing the shell or cartridge at the inner end of a hole, toplaster up the entire hole from the shell or cartridge therein to theouter end of the hole with clay. This necessity to plaster up the entirehole was the cause of substantial expense of time and money,inasmuch asthe clay and other material tobe used had to be brought into the mineand no little time was consumed in the work of plastering up all of theholes.

In view of these disadvantages encountered in the use of the drills usedheretofore, we have devised the drill disclosed herein, which drill isso constructed and arranged that a hole of uniform diameter may bedrilled therewith. When a shell or cartridge is fired in a hole which isof uniform diameter 1928. Serial m5. 292,939.

throughouh it has been found that it is entirely unnecessary to plasterup the entire hole from the shell or cartridge to the outer endofthehole. On the other hand, experiments haveproved that sealthe shell orcartridge in place in the hole by using a ping of clay which isapproximately four inches. in length. Thus the use of the drilldisclosed herein results in a great saving in time and material, wherebythe cost of the mining operation is materially reduced. Figure 1 is aside elevation of our im proved drill, a small portion thereof at therear of thedrill being shown in section.

Figure 2 is an enlarged section of a fragment of the drill at the headportion thereof. Figure 3 is an end elevation of the head portion of thedrill.

Figure iis a cross-section on line 44; of

Figure 2. a

l igure 5 is a perspective of one of the cutting elements'of the drill.a

l igure 6 is a perspective of another of the cutting elements of thedrill. a

Figure? is a fragmentary plan View of the rear or tail portion of thedrill.

Figure 8 isa View showing a modified form of the'invention.

Referring now to the drawings wherein is shown one embodiment merely ofour invention, A designates our Improved drill which comprisesgenerallya head portion B, a shank portion C, and a tail portion D. Theshank portion C is made up of a plurality of sections 1, 2, 3, and whichare secured together to provide a continuous memher, said sections beingtubular in form and each thereof having an internally screwthreadedportion 5 at one end and being provided with an extension 6 at theopposite end of slightly less diameter than the main body of thesection, which extension is externally "screw-threaded. To connecttogether the various sections of which the shank portion C is comprised,the screwthreaded' extensions 6 on said sections are screwed intointernally screw-threaded end portionsb of adjacent sections and whenthis is done a continuous, elongated member is provided. A a a a it isonly necessary to secured to saidsections.

of the shank portion 7 tion 10 Each of the sections comprising the shankportion C of ral conveyor '7, each of said sections being provided witha spiral groove 8 (Fig. 2) and the spiral conveyor, which comprises amember substantially L-sh'aped in cross-section is arranged with an edgeportion of one leg thereof seated in said spiral groove. 7 The other legof the L-shaped member extends parallel with the major axis of the shanksection, with which it is associated and said member is, of course,arranged spirally about the section. The spiral conveyors on the re-'spective sections making up the shank portion C of the drill and theexternal and internal screw-threads at the opposite ends of saidsections are so made with respect to each other that when adjacent shanksections are properly screwed together, the ends of. the

said adjacent shank secand therefore a complete drill comprised of apluspiral conveyors on .tions will colncide, shank portion of a ,ralityof sections will be provided with a continuous spiral conveyor from oneto the other end thereof. The spiral conveyors of the various sectionsare spot welded or otherwise Each of the sect ons making up theshankportion is provided with a plurality of apertures 9 formed throughthe wall thereof, through which fine particles of the core which passesthrough the nterior during the drilling operation may pass. A I Mountedat the forward end of the shank portion C is the head portion of thedrill already referred to, said head portion comrising a head 10 havinga tubular portion 10 of slightly less diameter thanthe main body portionof the head 10, and which s provided with internal screw-threads (Fig.2). The internally screw-threaded tubular poris screwed on theexternally screwthreaded extension 6 of the forward-most shank sectionand in this manner the head 10 is secured to the shank portion of thedrill.

The head 10 is tubular in form and the annular wall comprising the bodyportion of said head is provided with a plurality of slots 11 formedtherethrough, said slots being approximately radially arranged withrespect to p the head and being open at the forward edge of the headwhile extending rearwardly therein a substantial distance. Also the sidewalls of each of the slots 11 are approximately parallel with each otherand one wall of each slot is provided with an elongated depression 12formed therein which extends throughout -the slot. The circumferentialface of the head is provided with concave portions 13 which are locatedbetween pairs of slots 11 as shown in Fig. i'and through the annularwall providing the body portion of thehead openings 14 are formed topermit passage therethrough of fine particles of the core producedduring the drilling operation.

the drill is provided with a spi- Arranged in the plurality of slots- 11formed in the head 10 is a plurality of cutting elements 15, there beingone cutting.

element in each slot and each cutting element having a rib 16 formedthereon which is of such shape as to fit into the depression l2vdepressions 12. Each cutting element 15 adjacent to its rear end isprovided with a notch 17, andwhen the plurality of cutting elements areproperly arranged inplace'in the notches 11 of the head 10 the notches17 of the various cutting'elements willbe alined circumferentially ofthe head. In like manner, the portions ofthe head 10 located immediatelyat either side of each of the :slots 11 are provided with notches 17which coincidewith the notches 17 in the cutting elements. g

18 designates a split friction ring which 'is shaped to closely encirclethe head 10; that is to say the friction ring 18 is provided with curvedportions which fit closely within the concave portions between the slots11 of the head and portions 18' joining said curved portions together. 1To secure the, cutting elements in place in the slots 11 ofthe head thefriction ring 18 1s sprung'outwardly and is caused to encircle'the head10 sothat the portions 18 of said ring are seatedin the notches 17 ofthe cutting notches and the notches 17 forced in the head. The frictionring is characterized by atendencyto reduce its diameter and. thereforewill adhere close- 1y tothe head and because ofthe portions 18 passingthrough the notchesl'! .and 17 accidental displacement of said cuttingelements is prevented. 7,

By referring to Fig. ,3, it will be noted that the cutting noses onentering portions of the cutting elements 15 are located alternately inalinement with the outer and inner faces of the annular wall forming thebody portion of the head 10 so that cutting takes place on a pair ofcircular lines as the drill.v

moves into a body of coal. Also, each cutting element 15' has elongatedcutting edges 15 at opposite faces thereof.

Located at the rear, or tail position, of

the shank portion of the drill'i's atail piece 19,

said tail piece havingfan externallyscrewthreaded portion 19 whichscrews into an internally screwthreaded end portion of an adjacent shanksection to secure said tail piece to saidsh'ankportion. The tailrpiece19 is hollow as shown; in Fig. 1 andthe annular wall thereof isprovidedwith an opening 20 through which the broken coal comprising'thecore which isformedduring the drilling operation may pass from theinterior of the drill. The tail piece 19 is provided also with means 21at its extreme rear end which provides for the attachment of the entiredrill to an electrical drilling machine but as this means does not forma part of the present invention, it will not be described in detailherein.

In the use of a drill made in accordance with our invention, said drillis attached toa drilling machine or is operated manually in the usualand well known manner and it has been found that when a hole has beendrilled therewith, said hole is of uniform diameter throughout. Gne veryimportant advantage of our improved drill is that the cutting elementsare small and may be quickly and conveniently attached and detached fromthe drill head without special tools, hence a miner may carry a numberof these cutting elements into a mine and replace cutting elemcnts beingused when same have been dulled in use with sharp cutting elements.

If desired we may arrange the cutting elements 15 at a slight angle withrespect to the major axis of the head portionB as shown in Fig. 8. Whenthis arrangement is em ployed, the inclined side faces 15 of the cuttingelements during the operation of the drill, will function as conveyorswhich will move the drillings rearwardly away from the point at whichthe cutting is being done.

We claim:

1. A coal drill comprising a shank portion, a head at one end of saidshank portion, and a plurality of cutting elements individuallyremovably attached to said head, said head comprising a tubular memberprovided with a plurality of slots extended transversely entirelythrough the wall of said tubular member in which said cutting elementsare arranged, said cutting elements being extended beyond said head ina. forward direction, and the entering portions of said cutting elementsbeing arranged alternately in alineinent with the outer and inner facesof the annular wall comprising said tubular head, an extension on eachof said cutting elements seated in a depression formed in a wall of theassociated slot, and means comprising a split friction ring which isdisposed in apertures formed in the head and in the rear portions of thecutting elements whereby said cutting elements are tired to said head.

2. A coal drill including a shank portion comprising a plurality ofshank sections removabiy secured together, spiral members formed on saidshank sections, the spiral members in the various shank sections beingso arranged that when the plurality of shank sections are securedtogether to provide the shank portion of the drill, a continuous spiralmember will be extended from one to the other end of said shank portion,a head at one end of said shank portion, a plurality of cutting elementsremovably attached to said head, said head comprising a tubular memberrovided with a plurality of slots in whic 1 said cutting elements arearranged, an extension on each of said cutting elements seated in adepression formed in a wall of the associated slot, and means com risinga split friction ring which is dispose in apertures formed in the headand in the rear portions of the cutting elements whereby said cuttingelements are fixed to said head.

3. A coal drill including a shank portion comprising a plurality oftubular shank sections removably secured together by means of screwheadsformed thereon, spiral members formed on said shank sections, the spiralmembers in the various shank sections being so arranged that when theplurality of shank sections are secured together to provide the shankportion of the drill, a continuous spiral member will be extended fromone to the other end of said shank portion, a head at one end of saidshank portion, a plurality of cutting elements removably attached tosaid head, said head comprising a tubular member provided with aplurality of slots in which said cutting elements are arranged, anextension on each of said cutting elements seated in a depression formedin a Wall of the associated slot, and means comprising a split frictionring which is disposed in apertures formed in the head and in the rearportions of the cutting elements whereby said cutting elements are fixedto said head,

In testimony that we claim the foregoing we hereunto affix oursignatures.

CALVIN P. BASGOM. CHARLES WOLF.

